The present invention relates to a method of manufacturing a masked semiconductor laser.
Recording of information at high packing density has been made possible in recent years by optical memories and magnetooptic memories. Technical trends, however, are toward recording and reproducing of information at higher packing density. For reading recorded information from pits which are 0.4 to 0.5 micron across on an optical disk, it is necessary to reduce the diameter of a reading light beam to that range. However, presently available semiconductor lasers emit a light beam which has a longer diameter ranging from 3 to 6 microns and a shorter diameter ranging from 1 to 2 microns, for example, at the light-emitting spot. This size of the light-emitting spot makes it difficult to reduce the beam diameter to a level smaller than the wavelength of the laser beam, e.g., about 0.8 micron.